When there is no infrastructure in the network, then mobile ad hoc network is the best choice which is also less costly and easily deployable as in comparison. In such networks, in order to make them reliable and secure one need to analyze the routing mechanisms which are called as the MANET routing protocols. In this paper, the authors have to do the investigation of mobile ad hoc network protocols like Ad hoc On Demand routing protocol (AODV), Destination Sequence Distance Vector (DSDV) protocol using the different TCP types like TCP Reno, TCP Vegas and TCP NJ-plus.